Recent Advances in Platinum (IV) Complex‐Based Delivery Systems to Improve Platinum (II) Anticancer Therapy

Cisplatin and its platinum (Pt) (II) derivatives play a key role in the fight against various human cancers such as testicular, ovarian, head and neck, lung tumors. However, their application in clinic is limited due to dose‐ dependent toxicities and acquired drug resistances, which have prompted extensive research effort toward the development of more effective Pt (II) delivery strategies. The synthesis of Pt (IV) complex is one such an area of intense research fields, which involves their in vivo conversion into active Pt (II) molecules under the reducing intracellular environment, and has demonstrated encouraging preclinical and clinical outcomes. Compared with Pt (II) complexes, Pt (IV) complexes not only exhibit an increased stability and reduced side effects, but also facilitate the intravenous‐to‐oral switch in cancer chemotherapy. The overview briefly analyzes statuses of Pt (II) complex that are in clinical use, and then focuses on the development of Pt (IV) complexes. Finally, recent advances in Pt (IV) complexes in combination with nanocarriers are highlighted, addressing the shortcomings of Pt (IV) complexes, such as their instability in blood and irreversibly binding to plasma proteins and nonspecific distribution, and taking advantage of passive and active targeting effect to improve Pt (II) anticancer therapy.     

BMP-driven NRF2 activation in esophageal basal cell differentiation and eosinophilic esophagitis

Tissue homeostasis requires balanced self-renewal and differentiation of stem/progenitor cells, especially in tissues that are constantly replenished like the esophagus. Disruption of this balance is associated with pathological conditions, including eosinophilic esophagitis (EoE), in which basal progenitor cells become hyperplastic upon proinflammatory stimulation. However, how basal cells respond to the inflammatory environment at the molecular level remains undetermined. We previously reported that the bone morphogenetic protein (BMP) signaling pathway is critical for epithelial morphogenesis in the embryonic esophagus. Here, we address how this pathway regulates tissue homeostasis and EoE development in the adult esophagus. BMP signaling was specifically activated in differentiated squamous epithelium, but not in basal progenitor cells, which express the BMP antagonist follistatin. Previous reports indicate that increased BMP activity promotes Barrett’s intestinal differentiation; however, in mice, basal progenitor cell–specific expression of constitutively active BMP promoted squamous differentiation. Moreover, BMP activation increased intracellular ROS levels, initiating an NRF2-mediated oxidative response during basal progenitor cell differentiation. In both a mouse EoE model and human biopsies, reduced squamous differentiation was associated with high levels of follistatin and disrupted BMP/NRF2 pathways. We therefore propose a model in which normal squamous differentiation of basal progenitor cells is mediated by BMP-driven NRF2 activation and basal cell hyperplasia is promoted by disruption of BMP signaling in EoE.     

脐血干细胞与骨髓干细胞联合移植治疗大鼠急性肝衰竭实验研究

目的：观察脐血干细胞和自体骨髓干细胞共同移植治疗D-半乳糖苷所致急性肝衰竭大鼠的疗效。方法采集大鼠脐血和骨髓中单个核细胞,以促肝细胞生长因子和干细胞因子培养3w,采用免疫细胞化学法检测白蛋白和甲胎蛋白表达情况;以D-半乳糖苷腹腔注射法建立大鼠急性肝衰竭模型,24 h后每日经鼠尾静脉分别注入脐血干细胞,或骨髓干细胞,或混合的脐血干细胞和骨髓干细胞,对照组注射等量生理盐水,治疗7d,观察4组大鼠存活率、肝功能和肝组织病理学变化。结果在促肝细胞生长因子及干细胞因子的诱导下,脐血干细胞和骨髓干细胞可以在体外扩增并分化为肝细胞;脐血干细胞移植、骨髓干细胞移植和联合细胞移植组大鼠9d 存活率分别为55.6%、50.0%和77.8%,均明显高于生理盐水对照组（16.7%,P〈0.01）;联合移植组存活率高于任何一种单纯干细胞移植（P〈0.01）。结论脐血干细胞和骨髓干细胞移植对大鼠急性肝损伤有一定的保护作用,两者联合移植有协同作用。     

舒肝解郁胶囊联合稳心颗粒治疗心脏神经症的疗效观察

目的 探讨舒肝解郁胶囊联合稳心颗粒治疗心脏神经症的临床疗效。方法 选取2017年8月-2018年8月商洛市中心医院90例心脏神经症患者为研究对象,按照随机数字表法分成对照组及观察组两组,每组45例。对照组口服稳心颗粒治疗,观察组患者在对照组的基础上口服舒肝解郁胶囊治疗,治疗2个月后,比较两组患者的临床疗效、治疗前后两组患者各症状评分、24 h动态心电图结果及症状自评量表（SCL-90）评分变化。结果 治疗后,观察组患者治疗总有效率显著高于对照组（P<0.05）。治疗后,两组患者的各症状评分较治疗前均显著降低（P<0.05）,且观察组显著低于对照组（P<0.05）。治疗后,经24 h动态心电图检查两组患者早搏、心动过速、心动过缓、非特异性STT改变的发生率较治疗前均显著降低（P<0.05）,且观察组显著低于对照组（P<0.05）。治疗后,两组患者的SCL-90量表总分较治疗前均显著降低（P<0.05）,且观察组显著低于对照组（P<0.05）。结论 舒肝解郁胶囊联合稳心颗粒可有效改善心脏神经症患者的临床症状及心电图检查结果,对提高治疗效果、改善心理健康状态具有积极意义。     

One-electron oxidation of an oxoiron(IV) complex to form an [O═FeV═NR]+ center

Oxoiron(V) species are postulated to be involved in the mechanisms of the arene cis-dihydroxylating Rieske dioxygenases and of bioinspired nonheme iron catalysts for alkane hydroxylation, olefin cis-dihydroxylation, and water oxidation. In an effort to obtain a synthetic oxoiron(V) complex, we report herein the one-electron oxidation of the S = 1 complex [Fe^IV(O)(TMC)(NCCH₃)]²⁺ (1, where TMC is tetramethylcyclam) by treatment with tert -butyl hydroperoxide and strong base in acetonitrile to generate a metastable complex 2 at -44 °C, which has been characterized by UV-visible, resonance Raman, Mössbauer, and EPR methods. The defining spectroscopic characteristic of 2 is the unusual x/y anisotropy observed for the ⁵⁷Fe and ¹⁷O A tensors associated with the high-valent Fe═O unit and for the ¹⁴N A tensor of a ligand derived from acetonitrile. As shown by detailed density functional theory (DFT) calculations, the unusual x/y anisotropy observed can only arise from an iron center with substantially different spin populations in the d_xz and d_yz orbitals, which cannot correspond to an Fe^IV═O unit but is fully consistent with an Fe^V center, like that found for [Fe^V(O)(TAML)]^- (where TAML is tetraamido macrocyclic ligand), the only well-characterized oxoiron(V) complex reported. Mass spectral analysis shows that the generation of 2 entails the addition of an oxygen atom to 1 and the loss of one positive charge. Taken together, the spectroscopic data and DFT calculations support the formulation of 2 as an iron(V) complex having axial oxo and acetylimido ligands, namely [Fe^V(O)(TMC)(NC(O)CH₃)]⁺.     

胆汁内外引流术对梗阻性黄疸大鼠肺肿瘤坏死因子α、中性粒细胞弹性蛋白酶的影响

目的研究胆汁内外引流方法对梗阻性黄疸大鼠肺肿瘤坏死因子α(TNF-α)、中性粒细胞弹性蛋白酶(NE)水平的影响。方法将64只成年SD雄性大鼠随机分为4组,分别建立梗阻性黄疸(OJ)、胆汁内引流术(ID)、胆汁外引流术(ED)及假手术(SH)4组模型。于2次术后第14天留取肺组织匀浆液标本。采用双抗体夹心酶联免疫吸附法(ELISA)检测10%肺匀浆液TNF-α水平,生化法检测10%肺匀浆液NE水平。结果成功建立了大鼠梗阻性黄疸及内外引流术模型。梗阻性黄疸时大鼠肺TNF-α、NE水平较假手术对照组明显升高(100.893 pg/mL±21.271 pg/mL vs 64.091 pg/mL±13.034 pg/mL,P<0.01;50.396μg/mL±17.388μg/mL vs 39.718μg/mL±9.625μg/mL,P<0.05)。通过胆汁内引流术解除黄疸后,大鼠肺TNF-α浓度(75.141 pg/mL±15.849 pg/mL)与梗阻性黄疸组相比下降明显(P<0.01);而通过胆汁外引流术解除黄疸后,大鼠肺TNF-α浓度仍较高(112.129 pg/mL±36.886 pg/mL),与梗阻性黄疸组相比无差异(P>0.05)。行胆汁内、外引流术后,大鼠肺NE水平均降低(39.390μg/mL±12.410μg/mL、44.790μg/mL±16.681μg/mL),但与梗阻性黄疸组相比内引流明显(P<0.05)、外引流无差异(P>0.05),且内引流恢复至正常水平,与假手术对照组相比无差异(P>0.05)。结论梗阻性黄疸可导致肺组织炎症细胞因子升高,胆汁内引流术可明显改善梗阻性黄疸时肺组织炎症细胞因子水平、甚至接近正常,而胆汁外引流术没有改善肺炎症细胞因子水平,提示术前利用胆汁内引流术解除梗阻性黄疸缓解肺部炎症反应优于外引流术。